Cooperative Flow Management in Multi-domain SDN-based Networks with Multiple Controllers

The technology of software-defined networking (SDN) facilitates network management by adopting a controller to direct the operations of switches. This paper aims to efficiently manage flows in a multi-domain SDN-based (MDS) network, where each domain (i.e., subnetwork) is governed by a controller and there exist links between domains. To improve MDS performance, a cooperative flow management (CFM) framework is proposed in the paper. Each controller finds paths for the flows in its domain such that the loads of links can be balanced. When some links are still congested but there is no substitute path, the controller seeks help from neighboring domains. In this case, cross-domain paths will be constructed to replace congested paths. Since each controller finds paths based on only the local view of its own domain, CFM builds cross-domain paths in a cooperative, distributed manner. Through simulations, we verify that CFM can efficiently resolve congestion and significantly improve throughput.